RATE OF GROWTH OF MAGNESIUM OXIDE DEPOSITS FORMED BY SURFACE REACTION OF MAGNESIUM VAPOR AND OXYGEN

摘要

The rate of increase of the thickness of MgO deposits growing by-heterogeneous reaction of Mg vapor and O2 was measured. The deposits were formed on metal mirror surfaces that were prepared by vapor depos-ition of gold on glass slides. Interference fringes observed in sodium light were recorded photographically at time intervals suitable for measuring the rate of deposit growth. Under the conditions of the majority of the present experiments, the growth rates were found to be diffusion-controlled. Under these conditions, a lower limit of 7 x 10-2 was computed for the collision efficiency with respect to magnesium concentration. Preliminary experiments in the transition region between diffusion and chemical control indicate a higher collision efficiency, probably exceeding 0. 3.